A1 Journal article (refereed)
Organic matter lability modifies the vertical structure of methane-related microbial communities in lake sediments (2023)

Rissanen, A. J., Jilbert, T., Simojoki, A., Mangayil, R., Aalto, S. L., Khanongnuch, R., Peura, S., & Jäntti, H. (2023). Organic matter lability modifies the vertical structure of methane-related microbial communities in lake sediments. Microbiology Spectrum, 11(5), Article e01955-23. https://doi.org/10.1128/spectrum.01955-23

JYU authors or editors

Publication details

All authors or editors: Rissanen, Antti J.; Jilbert, Tom; Simojoki, Asko; Mangayil, Rahul; Aalto, Sanni L.; Khanongnuch, Ramita; Peura, Sari; Jäntti, Helena

Journal or series: Microbiology Spectrum

eISSN: 2165-0497

Publication year: 2023

Publication date: 12/09/2023

Volume: 11

Issue number: 5

Article number: e01955-23

Publisher: American Society for Microbiology

Publication country: United States

Publication language: English

DOI: https://doi.org/10.1128/spectrum.01955-23

Publication open access: Openly available

Publication channel open access: Open Access channel

Publication is parallel published (JYX): https://jyx.jyu.fi/handle/123456789/89134

Abstract

Eutrophication increases the input of labile, algae-derived, organic matter (OM) into lake sediments. This potentially increases methane (CH4) emissions from sediment to water through increased methane production rates and decreased methane oxidation efficiency in sediments. However, the effect of OM lability on the structure of methane oxidizing (methanotrophic) and methane producing (methanogenic) microbial communities in lake sediments is still understudied. We studied the vertical profiles of the sediment and porewater geochemistry and the microbial communities (16S rRNA gene amplicon sequencing) at five profundal stations of an oligo-mesotrophic, boreal lake (Lake Pääjärvi, Finland), varying in surface sediment OM sources (assessed via sediment C:N ratio). Porewater profiles of methane, dissolved inorganic carbon (DIC), acetate, iron, and sulfur suggested that sites with more autochthonous OM showed higher overall OM lability, which increased remineralization rates, leading to increased electron acceptor (EA) consumption and methane emissions from sediment to water. When OM lability increased, the abundance of anaerobic nitrite-reducing methanotrophs (Candidatus Methylomirabilis) relative to aerobic methanotrophs (Methylococcales) in the methane oxidation layer of sediment surface decreased, suggesting that Methylococcales were more competitive than Ca. Methylomirabilis under decreasing redox conditions and increasing methane availability due to their more diverse metabolism (fermentation and anaerobic respiration) and lower affinity for methane. Furthermore, when OM lability increased, the abundance of methanotrophic community in the sediment surface layer, especially Ca. Methylomirabilis, relative to the methanogenic community decreased. We conclude that increasing input of labile OM, subsequently affecting the redox zonation of sediments, significantly modifies the methane producing and consuming microbial community of lake sediments.

Keywords: greenhouse gases; fresh water; eutrophication; lakes; emissions

Free keywords: greenhouse gas; freshwater; methanotroph; methanogen; 16S rRNA gene; eutrophication

Contributing organizations

Ministry reporting: Yes

VIRTA submission year: 2023

JUFO rating: 2